Gas operated firearm muzzle attachment

ABSTRACT

A gas operated firearm muzzle attachment for generating sufficient gas pressure in the barrel to operate the firearm gas system when blank cartridges are used and comprising a solid restrictor insertable into the barrel bore to partially block the escape of discharge gases therefrom and a clamp for quickly and easily mounting the restrictor to the barrel.

United States Patent Csizmar et al. 1 Aug. 29, 1972 [54] GAS OPERATED FIREARM MUZZLE 680,327 8/1901 Hay ..89/14 E ATTACHMENT 3,440,924 4/1969 Sawyer ..89/ 14 E [72] Inventors: John R. Csizmar; Herbert A.

rmary Examiner-Ben amin A. Borchelt Hebeler both of Davenport Iowa Assistant ExaminerC. T. Jordan [73] Assignee: The United States of America as Attorney-Harry M. Saragovitz, Edward J. Kelly, Herrepresented by the Secretary of the bert Berl and Albert E. Arnold, Jr. Army [22] Filed: April 30, 1970 [57] ABS CT A gas operated firearm muzzle attachment .for [21] 33456 generating sufi'rcient gas pressure in the barrel to operate the firearm gas system when blank cartridges [52] US. Cl. ..89/14 E are used and comprising a solid restrictor insertable [51] Int. Cl. ..F4lf 17/12, F41c 21/18 into the barrel bore to partially block the escape of [58] Field of Search ..89/ 14 E, 14 R discharge gases therefrom and a clamp for quickly and easily mounting the restrictor to the barrel. [56] References Cited 8 Claims 4]) UNITED STATES PATENTS 2,356,538 8/1944 Schmeisser ..89/14 E A 2o All GAS OPERATED FIREARM MUZZLE ATTACHMENT The invention described herein may be manufac tured, used, and licensed by or for the Government for governmental purposes without the payment to us of any royalty thereon.

BACKGROUND OF THE INVENTION This invention relates to attachments for muzzles of firearm barrels and pertains more particularly to a muzzle attachment for gas operated firearms to provide automatic operation thereof when firing blank cartridges.

For both safe and economical reasons, it is advisable in the training of troops to fire blank cartridges in firearms to simulate actual firing conditions. When the firearms are operated by gas pressure produced by the discharge of cartridges, an attachment must be mounted to the muzzle of the firearm ban-e1, when blank cartridges are used, so as to at least partially block the escape of gases therefrom and thereby generate 'sufficient back pressure to operate the firearm gas system. .p It has been found that these attachments are quickly eroded beyond safe limits, and are also easily mislaid which is costly as present attachments are complex as to structure and therefore are relatively expensive to manufacture.

SUMMARY OF THE INVENTION It is, therefore, a principal object of this invention to provide for gas operated firearms a blank firing attachment which is economically manufactured and is easily installed on the firearm barrel.

It is a further object of this invention to provide such an attachment which comprises only two pieces, a

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a longitudinally cross-sectioned view of the blank firing attachment of this invention mounted to a firearm barrel;

, FIG. 2 is a perspective view of the attachment mounted to a firearm barrel;

FIG. 3 is a perspective view of the attachment with the jaws shown in their open positions; and

FIG. 4 is a fragmentary, cross-sectional view taken along line 4-4 of FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT Shown in the figures is a barrel 12 of a firearm which is arranged for automatic operation by gas pressure produced by the discharge of cartridges therein. The barrel is provided with a muzzle mounted flash suppressor 14 in which an annular groove 16 is formed in the outer surface adjacent to the rear portion thereof.

Shown installed on the muzzle end of barrel 12 is a blank firing attachment 20 whereby sufficient gas pressure is generated in the barrel when blank cartridges are fired therein for practise purposes to operate the firearm gas system. Attachment 20 comprises two parts, a restrictor 22 and a clamp 24. Restrictor 22, when inserted into bore 26 of barrel 12, at least partially blocks the escape of discharge gases therefrom, and clamp 24 functions to quickly and easily mount the restrictor to the barrel and releasably hold it therein.

Restrictor 22 is of solid cylindrical configuration and is of a length to extend through attachment 20 into bore 26. The diameter of restrictor 22 is so related to the diameter of bore 26 that when a blank cartridge is fired therein approximately the same gas pressure is momentarily generated E the bore as would be generated when a cartridge with a projectile :is fired therein. For example the bore diameter is 0.222 inches, a diameter of 0.203 inches for restrictor 22 has been found to be effective. Formed on the front portion of restrictor 22 so as to be spaced from the front end thereof is an annular flange 32 which assists in securing the restrictor to clamp 24, as hereinafter described.

Clamp 24 is preferably formed as by stamping process from a single piece of sheet metal having resilient qualities and comprises a circular embossed portion 36 that forms a rearwardly facing pocket 38 for receiving the front end of flash suppressor 14 when attachment 20 is mounted thereon. An aperture 40 is punched centrally through embossed portion 36 from the front side thereof to form a rearwardly projecting annular flare 42. To assemble clamp 24 and restrictor 22 the front end of the restrictor is inserted into flare 42 until flange 32 contacts the rear edge thereof. The front end of restrictor 22 is then peened over, as indicated at 30, to retain restrictor 22 and clamp 24 together. Embossed portion 36 is so dimensioned that pocket 38 locates on the outside diameter of flash sup pressor 14 to align restrictor 22 with bore 26, as shown in FIG. 1. Further assistance in aligning restrictor 22 with bore 26 is provided by the engagement of flange 32 with the inside diameter of flash suppressor l4. Flange 32 is also dimensioned to function as a shear area, permitting separation of restrictor 22 and clamp 24 in case a cartridge with a projectile is accidentally fired in barrel 12 when attachment 20 is installed thereon.

Extending diametrically opposite from embossed portion 36 is a pair of leaf springs 44 each of which is of U-configuration in longitudinal cross section, as shown in FIG. 1, and includes an arm 46 that extends inwardly at right angles from the rear end of a longitudinally disposed hand gripping portion 48. Leaf springs 44 extend along the length of flash suppressor 14 so that jaws 50, formed as extensions of arms 46, are engageable with groove 16 in the flash suppressor when hand gripping portions are squeezed inwardly. When leaf springs 44 are unloaded, as shown in FIG. 3, jaws 50 are opened sufficiently to perit the passage thereof over flash suppressor 14 when attachment 20 is mounted thereto. Jaws 50, when squeezed together against the bias of leaf springs 44 into engagement with channel 16, as shown in FIGS. 1 and 2, are disposed normal to the longitudinal axis of flash suppressor 14.

Referring to the illustrations of attachment 20 in the drawing for the hereinafter described relationship of the reference elements, jaws 50 are seen to include an upper jaw 52 and a lower jaw 54. Upper jaw 52 is provided with an areuate recess 56, which has approximately the same radius as groove 16, and is formed in the bottom edge thereof so as to fit into and around such groove for full engagement therewith when the hand gripping portion 48 respective thereto is squeezed inwardly. Extending laterally from opposite sides of upper jaw 52 is a pair of locking bars 58 each of which projects outwardly from and below a vertically disposed edge 60 of the upper jaw.

Lower jaw 54 includes an arcuate lip 62 which has substantially the same radius as groove 16 and which is offset forwardly from the remainder of the lower jaw so as to be receivable by the groove while the remaining portion of the jaw is located rearwardly of upper jaw 52, to permit passage thereby during relative displacement of jaws 50. Extending laterally and upwardly from opposite sides of lower jaw 54 is a pair of latch portions 66 of leaf configuration, which are resiliently displaceable about a lateral axis relative to attachment 20. Each of the latch portions 66 is provided with a tab 68 of rectangular configuration which is pierced therefrom and bent so as to extend downwardly and forwardly from the front face of the respective latch portion to form a recess 70 which is open at the sides and bottom between the tab and the front surface. Thus, locking bars 58 are permitted upward entry behind tabs 68 for releasably holding jaws 50 closed, as shown in FIG. 4. With jaws S closed, inner side 72 of each of the tabs 68 is in close contact with one of the edges go of upper jaw through open 52, as shown in FIG. 4, to prevent relative side movement between lower jaw 54 and upper jaw 52.

Attachment is installed on barrel 12 by passing flash suppressor 14 through open jaws 50 so that the free end of restrictor 22 is inserted through flash suppressor 14 into bore 26. At the same time, the front end of the flash suppressor is received by pocket 38 to hold the restrictor aligned with the bore. Hand gripping portions 48 are then manually squeezed together against the bias of leaf springs 44 to move locking bars 58 downwardly in front of latching portions 66 and into camming contact with the front surfaces of tabs 68. Continued squeezing pressure on hand gripping portions 48 moves jaws 50 into engagement with groove 16 while locking bars 58 move along the front surfaces of tabs 68, causing latching portions 66 to be resiliently displaced, until the locking bars snap off the ends of the tabs. Thus, when the squeezing pressure applied to hand gripping portions 48 is released and lower jaw 54 and upper jaw 52 are pressed apart through the bias of the energized leaf springs 44, locking bars 58 enter recesses 70 and are located behind the respective tabs 68 to hold the jaws closed and in secure engagement with groove 16.

Attachment 20 is removed from barrel 12 by squeezing inwardly on hand gripping portions 48 until locking bars 58 are moved out of recesses 70 and then pulling rearwardly on latching portions 66 to where tabs 68 are free of the locking bars. Jaws 50 are thereby free to open through the bias of leaf springs 44.

We wish to be understood that we do not desire to be limited to the exact details of construction shown and described. for obvious modifications will occur to a person skilled in the art.

We claim:

1. An attachment to the muzzle of a firearm barrel having a flash suppressor attached thereto, said attachment comprising a restrictor insertable into said barrel muzzle for partial restriction thereof and a clamp of unitary construction for releasably securing said restrictor to said barrel muzzle, said clamp being fabricated from a resilient material and comprising an embossed portion forming a pocket for receiving the front end of said flash suppressor in response to attachment to said barrel muzzle, an aperture centrally located in said embossed portion, a flared portion associated with said aperture disposed for receiving one end of said restrictor, means on said restrictor cooperating with said flared portion for fixedly securing said restrictor to said clamp, and said means being disposed for cooperation with said flash suppressor and said pocket for aligning said restrictor with said barrel muzzle.

2. The invention as defined in claim 1 and including integral jaw means on said clamp engageable with an annular groove in said flash suppressor for releasably securing said attachment to said suppressor.

3. The invention as defined in claim 1 wherein said clamp comprises a pair of leaf springs extending oppositely from said embossed portion, each of said leaf springs being of U-configuration in longitudinal cross section and comprising a hand gripping portion extending along the length of said flash suppressor and an arm extending inwardly at right angles from said hand gripping portion toward said flash suppressor, anda pair of jaws extending from said arms for engagement with said groove in response to said hand gripping portions being manually squeezed together.

4. The invention as defined in claim 3 wherein said jaws are normally disposed in spaced apart relation a distance greater than the diameter of said groove.

5. The invention as defined in claim 3 wherein said leaf springs include means for releasably securing said jaws in a closed position in response to engagement with said groove.

6. The invention as defined in claim 5 wherein said means for securing said jaws closed comprises a pair of locking bars extending oppositely from one of said pair of jaws, a pair of latching portions of leaf configuration extending oppositely from the other one of said pair of jaws and arranged to be resiliently displaceable about a lateral axis respective to said attachment, and a tab formed on each of said latching portions for cooperation with a respective one of said locking bars to releasably hold said jaws closed.

7. The invention as defined in claim 6 wherein each of said tabs comprises a portion of said latching portions disposed on opposite sides of the respective jaw portion and providing a recess open at both sides and the bottom formed between said tab and said latching portion to receive the respective one of said locking bars in response to said hand gripping portions being squeezed together sufficiently to engage said jaws with said groove.

8. The invention as defined in claim 6 wherein said means on said restrictor cooperating with said flared portion includes a flange dimensioned to function as a shear area thereby to permit separation of said clamp from said restrictor in response to a projectile in said barrel engaging said restrictor. 

1. An attachment to the muzzle of a firearm barrel having a flash suppressor attached thereto, said attachment comprising a restrictor insertable into said barrel muzzle for partial restriction thereof and a clamp of unitary construction for releasably securing said restrictor to said barrel muzzle, said clamp being fabricated from a resilient material and comprising an embossed portion forming a pocket for receiving the front end of said flash suppressor in response to attachment to said barrel muzzle, an aperture centrally located in said embossed portion, a flared portion associated with said aperture disposed for receiving one end of said restrictor, means on said restrictor cooperating with said flared portion for fixedly securing said restrictor to said clamp, and said means being disposed for cooperation with said flash suppressor and said pocket for aligning said restrictor with said barrel muzzle.
 2. The invention as defined in claim 1 and including integral jaw means on said clamp engageable with an annular groove in said flash suppressor for releasably securing said attachment to said suppressor.
 3. The invention as defined in claim 1 wherein said clamp comprises a pair of leaf sprinGs extending oppositely from said embossed portion, each of said leaf springs being of U-configuration in longitudinal cross section and comprising a hand gripping portion extending along the length of said flash suppressor and an arm extending inwardly at right angles from said hand gripping portion toward said flash suppressor, and a pair of jaws extending from said arms for engagement with said groove in response to said hand gripping portions being manually squeezed together.
 4. The invention as defined in claim 3 wherein said jaws are normally disposed in spaced apart relation a distance greater than the diameter of said groove.
 5. The invention as defined in claim 3 wherein said leaf springs include means for releasably securing said jaws in a closed position in response to engagement with said groove.
 6. The invention as defined in claim 5 wherein said means for securing said jaws closed comprises a pair of locking bars extending oppositely from one of said pair of jaws, a pair of latching portions of leaf configuration extending oppositely from the other one of said pair of jaws and arranged to be resiliently displaceable about a lateral axis respective to said attachment, and a tab formed on each of said latching portions for cooperation with a respective one of said locking bars to releasably hold said jaws closed.
 7. The invention as defined in claim 6 wherein each of said tabs comprises a portion of said latching portions disposed on opposite sides of the respective jaw portion and providing a recess open at both sides and the bottom formed between said tab and said latching portion to receive the respective one of said locking bars in response to said hand gripping portions being squeezed together sufficiently to engage said jaws with said groove.
 8. The invention as defined in claim 6 wherein said means on said restrictor cooperating with said flared portion includes a flange dimensioned to function as a shear area thereby to permit separation of said clamp from said restrictor in response to a projectile in said barrel engaging said restrictor. 